Generally, a variety of electron cyclotron resonance ion sources are used in many applications because ions can be generated at relatively low cost. The electron cyclotron resonance ion sources are used in various forms in many applications.
For example, there have been several successful proposals for large-area ionization using a permanent magnet for material etching and a solenoid mirror electromagnet with a copper wire having a cooling channel inside. In addition, studies are being carried out about X-ray ion source as a safe, compact, inexpensive and, in particular, portable ion source, although further efforts are necessary for beam integration and guiding since the image resolution is not enough and the emission area is large.
Further, electron cyclotron resonance is employed as an ion injection source of a heavy-ion linear accelerator and a cyclotron for generating radioactive isotopes for medical and material research.
However, when a permanent magnet or a combination of solenoid electromagnets is used to generate a large-area mirror magnetic field, a space of ten to hundreds times that of the area of the magnetic field needed in the ionizing chamber housing is required for installation of the magnet. This inevitably increases the apparatus size and becomes a hindrance to increasing the ionization area.
A stronger mirror magnetic field is required to improve resolution of X-ray images and generate multiply charged ions for a particle accelerator. For this, use of a superconducting magnet has been found useful. However, since it requires an additional device to keep cryogenic temperatures, problems of portability and maintenance cost remain. Recently, a refrigerator was used solve the portability problem and various efforts are being made to reduce the maintenance cost. However, such application is restricted due to the use of expensive superconducting wire. Moreover, it is expected that the limit of the critical magnetic field will soon be reached. Therefore, developing an ion source capable of replacing those that currently exist is desirable.